The Upaniṣads

उपनिषद्

Also written: upanishads · 108 upanishads · principal upanishads · vedanta · mahavakya · उपनिषद्

Upa-ni-ṣad: to sit down near. The word describes the situation — a student seated close to a teacher, receiving what is not shouted across a hall. The Upaniṣads are the fourth and final layer of the Veda, and they are called Vedānta, the end of the Veda, in both senses: the last part, and the conclusion.

The question they are all answering

The Upaniṣads are not organised around a doctrine but around a question, and the Muṇḍaka states it with unusual sharpness. Śaunaka, a great householder, approaches Aṅgiras in the prescribed manner and asks one thing.

कस्मिन्नु भगवो विज्ञाते सर्वमिदं विज्ञातं भवतीति।

kasmin nu bhagavo vijñāte sarvam idaṁ vijñātaṁ bhavatīti

Sir, what is that, knowing which, all this becomes known?

— Muṇḍaka Upaniṣad 1.1.3

That is a request for a specific logical form — not for a great deal of knowledge but for the one item whose knowledge entails the rest. It presupposes that reality has such an item, which is a substantial metaphysical bet, and every Upaniṣad is in one way or another an answer to it. Uddālaka gives the analogy in the Chāndogya: knowing clay, one knows every clay pot, since the pot is a modification of speech, a name, and the clay alone is real. The question also explains why the answer is never a list of facts. A fact does not have the property Śaunaka is asking about; only a substrate does.

How many

The Muktikā Upaniṣad lists 108. Of these, ten are commented on by Śaṅkara and are called the principal Upaniṣads; adding Śvetāśvatara, Kauṣītaki and Maitrāyaṇīya gives the thirteen usually treated as the classical set. The remainder group into Sāmānya (general), Yoga, Sannyāsa, Śākta, Vaiṣṇava and Śaiva Upaniṣads.

The ten principal Upaniṣads
Upaniṣad	Veda	Known for
Īśa	Śukla Yajur	18 verses; the world pervaded by the Lord; action and renunciation reconciled
Kena	Sāma	'By whom is the mind sent forth?' — that which the mind cannot think but by which mind thinks
Kaṭha	Kṛṣṇa Yajur	Naciketas and Yama; the chariot of the self; 'arise, awake, and stop not'
Praśna	Atharva	Six questions on prāṇa, the syllable Om and the person
Muṇḍaka	Atharva	Higher and lower knowledge; the two birds on one tree; 'satyameva jayate'
Māṇḍūkya	Atharva	Twelve verses; the four states of consciousness and the four mātrās of Om
Taittirīya	Kṛṣṇa Yajur	The five sheaths; 'brahmavid āpnoti param'; the graduation address
Aitareya	Ṛg	Creation from the Self; 'prajñānaṁ brahma'
Chāndogya	Sāma	'Tat tvam asi'; Śvetaketu; the honey doctrine; Sanatkumāra and Nārada
Bṛhadāraṇyaka	Śukla Yajur	The largest; Yājñavalkya and Maitreyī; 'neti neti'; 'ahaṁ brahmāsmi'

The four mahāvākyas

One great sentence is drawn from each of the four Vedas. Together they state the entire position of Vedānta.

Mahāvākya	Sanskrit	Meaning	Source
Prajñānaṁ brahma	प्रज्ञानं ब्रह्म	Consciousness is Brahman	Aitareya Up. 3.3 — Ṛgveda
Ahaṁ brahmāsmi	अहं ब्रह्मास्मि	I am Brahman	Bṛhadāraṇyaka Up. 1.4.10 — Yajurveda
Tat tvam asi	तत्त्वमसि	That thou art	Chāndogya Up. 6.8.7 — Sāmaveda
Ayam ātmā brahma	अयमात्मा ब्रह्म	This Self is Brahman	Māṇḍūkya Up. 2 — Atharvaveda

What they actually do

The Upaniṣads are not a creed. They are almost entirely made of questions — a student asks, a teacher answers, and the answer is frequently another question. Naciketas refuses wealth and long life in order to ask what happens after death. Maitreyī asks her husband what use wealth is if it cannot make her immortal. Nārada, master of every science, tells Sanatkumāra that he knows all the texts and still grieves.

उत्तिष्ठत जाग्रत प्राप्य वरान्निबोधत।

uttiṣṭhata jāgrata prāpya varān nibodhata

Arise, awake, and learn by approaching the excellent ones.

— Kaṭha Upaniṣad 1.3.14 — first line

Three images that carry the whole teaching

Where the Upaniṣads do assert, they usually do it in an image rather than a proposition, and three of those images do most of the work. The first is the two birds — a verse so old that it stands in the Ṛgveda before the Muṇḍaka takes it up.

द्वा सुपर्णा सयुजा सखाया समानं वृक्षं परिषस्वजाते। तयोरन्यः पिप्पलं स्वाद्वत्त्यनश्नन्नन्यो अभिचाकशीति॥

dvā suparṇā sayujā sakhāyā samānaṁ vṛkṣaṁ pariṣasvajāte tayor anyaḥ pippalaṁ svādv atty anaśnann anyo abhicākaśīti

Two birds, companions joined together, cling to the same tree. One of them eats the sweet fig; the other, not eating, looks on.

— Muṇḍaka Upaniṣad 3.1.1 (= Ṛgveda 1.164.20)

Sayujā sakhāyā — joined, companions. The two are not opposed and not separable, and they are on one tree. The eating bird is the individual caught in experience; the watching bird is the same consciousness not identified with what it observes. Note that the watcher does not intervene, does not judge and does not eat: the verse describes a shift of standpoint, not a change of behaviour, and the next verse says that grief ends when the eater sees the other and knows its greatness. This single image is the seed of the Sāṅkhya distinction between puruṣa and prakṛti, the Gītā's field and knower of the field, and the whole practice of witness-consciousness.

The second is the sentence Uddālaka repeats to his son nine times, each time after a different demonstration.

स य एषोऽणिमैतदात्म्यमिदं सर्वं तत्सत्यं स आत्मा तत्त्वमसि श्वेतकेतो।

sa ya eṣo'ṇimaitad-ātmyam idaṁ sarvaṁ tat satyaṁ sa ātmā tat tvam asi śvetaketo

That which is this subtlest essence — this whole world has that as its self. That is the real. That is the Self. That thou art, Śvetaketu.

— Chāndogya Upaniṣad 6.8.7

The force is in the sequence. Tat satyam — that is the real; sa ātmā — that is the Self; and only then tat tvam asi. The identity is not asserted directly between the student and the absolute; it is derived, in three steps, from a chain the student has just been walked through with salt dissolved in water, with a fig seed opened, with rivers running into the sea. And the teaching is repeated nine times because Śvetaketu says, each time, bhūya eva mā bhagavān vijñāpayatu — 'let my lord instruct me further'. The most famous sentence in Indian philosophy is the answer to a student who kept saying he had not understood.

The third is the invocation recited before the Īśa and the Bṛhadāraṇyaka, which states the relation of the whole to the whole.

पूर्णमदः पूर्णमिदं पूर्णात्पूर्णमुदच्यते। पूर्णस्य पूर्णमादाय पूर्णमेवावशिष्यते॥

pūrṇam adaḥ pūrṇam idaṁ pūrṇāt pūrṇam udacyate pūrṇasya pūrṇam ādāya pūrṇam evāvaśiṣyate

That is full; this is full. From the full, the full proceeds. Taking the full from the full, the full alone remains.

— Bṛhadāraṇyaka Upaniṣad 5.1.1

The verse is doing arithmetic that ordinary arithmetic cannot do: a quantity from which a quantity is removed and which is unchanged. That is not mysticism dressed as paradox — it is a precise statement that the infinite does not behave like a finite stock, and that creation therefore cannot be subtraction from a reservoir. Mathematicians will recognise the property that distinguishes an infinite set from a finite one, and the recognition is fair, though it should be put no more strongly than that: the Upaniṣad is not doing set theory, it is stating the one property of fullness that makes emanation possible without loss.

The Upaniṣads

The question they are all answering

How many

The four mahāvākyas

What they actually do

Three images that carry the whole teaching

In this section

The principal Upaniṣads, one by one

The Yoga Upaniṣads

The sources of knowledge in Sanātana Dharma

Śruti — that which was heard

Smṛti — that which was remembered

Nigama and Āgama — the two revealed streams

The four Vedas

Ṛgveda